1. Field of the Invention
This invention relates to an image formation apparatus such as a copier or a printer and method for controlling the same and in particular to an art of controlling a paper stop position when an anomaly of a paper jam occurs.
2. Description of the Related Art
In recent years, demands for forming an image on paper having various sizes, thicknesses, and paper qualities (coated paper, cardstock, transparencies, or the like) have been made for an image formation apparatus such as a copier or a printer. To transport various types of paper in an image formation apparatus, it is necessary to control a position of paper being transported in response to the paper type. For example, to transport thick paper, the pitch interval of paper (reference timing of delivering paper) is extended more than that to transport thin paper or in case of forming an image on both sides of paper (double-sided copying), the pitch interval of paper is thinned out for controlling the position of paper being transported. Thus, the positions of paper being transported in the image formation apparatus have various patterns.
When an anomaly of a paper jam occurs during an operation of the image formation apparatus and it becomes necessary to stop transporting paper accordingly, if transporting the paper is stopped at the same time as the anomaly occurs, it is feared that the paper stop position may become improper. For example, if the paper being transported is stopped at the same time as a paper jam occurs (is detected), it is also assumed that when the jammed paper is removed, the paper stopped at an improper position will be torn off and a paper piece that cannot be removed will remain in the apparatus, resulting in an inoperable state. Thus, if an anomaly as described above occurs, control is performed so as to stop the paper at a position where the paper can be removed easily. To realize such paper stop position control, it is necessary to predetermine which positions paper should be stopped at in response to anomaly contents (for example, if the anomaly is a paper jam, the occurrence point) and a position of the paper being transported at a time when the anomaly occurs.
By the way, a postprocessing unit for taking paper on which an image is already formed therein to perform postprocessing of collating, stacking, stapling or the like may be added to a main unit of an image formation apparatus. In such a case, if a paper jam occurs in the postprocessing unit attached (joined) to the main unit of the image formation apparatus, it becomes almost impossible to locate the paper position in the main unit of the image formation apparatus. Thus, it is impossible to stop the paper being transported at a proper position in the main unit of the image formation apparatus. Then, to remove the jammed paper, it is feared that a paper piece remains that cannot be removed because of torn-off paper as described above.
In the case of a paper jam occurring in the main unit of the image formation apparatus, the position of paper being transported varies depending on the paper type and thus if an attempt is made to properly control the stop positions of all types of paper, the paper stop patterns also become various and it becomes extremely intricate to control stopping paper.
An object of the invention is to solve the above described problems.
According to the invention, there is provided an image formation apparatus comprising a first apparatus unit having a first paper transport passage; a second apparatus unit having a second paper transport passage for passing paper to/from the first paper transport passage; and a controller, wherein the controller causes a paper jam to occur in the first apparatus unit when an anomaly requiring that paper transporting be stopped in the second apparatus unit; and the controller controls a paper stop position in the first apparatus unit based on the paper jam caused to occur.
In the image formation apparatus having the above described configuration, if an anomaly requiring that paper transporting be stopped (for example, a paper jam) occurs in the second apparatus unit, the controller causes a paper jam to occur in the first apparatus unit, and the controller controls the paper stop position in the first apparatus unit based on the paper jam. Accordingly, it is made possible to appropriately control the paper stop position in the first apparatus unit regardless of the timing at which an anomaly occurs in the second apparatus unit.
According to the invention, there is provided a control method of an image formation apparatus comprising a first apparatus unit having a first paper transport passage and a second apparatus unit having a second paper transport passage for passing paper to/from the first paper transport passage, the control method comprising the steps of: causing a paper jam to occur in the first apparatus unit when an anomaly requiring that paper transporting be stopped in the second apparatus unit; and controlling a paper stop position in the first apparatus unit based on the paper jam.
In the control method of the image formation apparatus, when an anomaly requiring that paper transporting be stopped occurs in the second apparatus unit, a paper jam is caused to occur in the first apparatus unit, and the paper stop position in the first apparatus unit is controlled based on the paper jam. Thus, it is made possible to appropriately control the paper stop position in the first apparatus unit regardless of the timing at which an anomaly occurs in the second apparatus unit.